抄録
The effects of enzymic or chemical fragmentations and of chemical modifications on the antigenic properties of bovine β-lactoglobulin were examined using specific mouse IgE antibody. The antigenic reactivity of β-lactoglobulin derivatives was represented in terms of their ability to neutralize specific IgE antibodies assayed by passive cutaneous anaphylaxis in rat. The tryptic, chymotryptic or peptic hydrolysate free of native β-lactoglobulin had no antigenic reactivity but the fragments obtained after CNBr cleavage retained the ability to bind the antibody. Modification of the sulfhydryl group, arginine or tryptophan residues and amino groups had no effect on antigenic reactivity but a little decrease in the reactivity was observed on the cleavage of the two disulfide bridges. These results suggest that one sulfhydryl group, two arginine and tryptophan residues and most of the amino groups are out of antigenic sites in β-lactoglobulin and that the antigenicity depends on the conformation maintained by the disulfide bridges.
